Furnace wall and brick therefor



Dec. 25, 1928.

O. NYGAARD ET AL FURNACE WALL AND BRICK THEREFOR 2 Sheets-Sheet 1 FiledFeb. 5, 1926 INVENTORS My WWW By A TTORNEY.

Dec 25, 1928.

O. NYGAARD ET AL FURNACE WALL AND BRICK THEREFOR 2 Sheets-Sheet 2 FiledFeb. 1926 l N V EN TORS 2' TM 414% TTORYVEY.

Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

OSCAR NYGAARD, OF SAUGUS, AND BENJAMIN H. SNOW, OF WEST MEDFORD, MASSA-CHUSETTS, ASSIGNORS TO BERNITZ FURNACE APPLIANCE COMPANY, OF BOSTON,MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

FURNACE WALL AND BRICK THEREFOR.

Application filed February 3, 1926.

This invention relates to furnace walls and to bricks for use in theconstruction of such walls.

Air cooled furnace walls of the general type shown, for example, in theBernitz Patent No. 1,393,606 are now used quite comnionly, especially inthose installations which are subjected to sustained operation at hightemperatures. This type of wall, if properly built, has a much longerlife than walls of prior constructions, it effects important economiesin maintenance, and reduces very matcrially the interruptions in servicenecessitated by the rebuilding or repairing of furnace walls. Thepresent invention aims to improve and perfect furnace wall constructionsof the general character above designated with a view to effectingfurther economies in the building and up-keep of such walls. while atthe same time improving the mechanical strength and rigidity of walls ofthis type. The invention also provides a brick of novel constructionwhich is especially adapted for use in building walls of the characterabove indicated. While we have referred to said Bernitz patent by way ofexample, it is tobe understood that the uses of our invention are notlimited to what is shown therein but extend to any air cooled furnacewall, such walls having a wide Va riety of uses, as in pulverized fuelfurnaces, etc.

The nature of the invention will be readily understood from thefollowing description when read in connection with the accompanyindrawings. and the novel features will be particularly pointed out in theappended claims.

In the drawings,

Figure 1 is a front elevation of a. portion of a furnace wallconstructed in accordance with this invention;

Figs. 2, 3 and 4 are cross-sectional views on the lines 22, 33 and 1-4,respectively, of Fig. 1;

Fig. 5 is a perspective view of a novel form of brick embodying onefeature of this invention;

Figs. 6 and 7 are top and front Views of a modified construction .ofbrick;

Fig. 8 is a front view of a further modiiication;

Serial No. 85,682.

F ig. 9 is a side view of still another form of brick; and

Fig. 10 is a perspective View of a brick somewhat like, but differentfrom, the construction shown in Fig. 5.

Referring firstto Figs. 1 to 4, inclusive, it will be observed that thewall there shown comprises a rear section A and a front section B. Therear section usually is made of ordinary fire brick laid up in the usualman ner, while the front section is composed of special bricks, arrangedin superposed courses, with the bricks in one course breaking jointswith those in the next course.

In the drawings only four of these courses are shown, although thisnumber obviously may vary with the requirements of each individualinstallation. The bricks or blocks C in the uppermost course are ofbox-like form and have a relatively thin front wall or body portion withupright flanges 2-2, Figs. 3 and 4, projecting rearwardly from oppositeends thereof, and horizontal flanges 3-3 projecting rearwardly from thetop and bottom thereof. Each of the Vertical flanges has a deep notch 4formedthrough it laterally and these'notches in adjacent blocks registerwith each other and afford lateral communication between the spaces orchambers in the adjacent blocks C. Similarly, each horizontal flange 3has a notch 5, Fig. 3, formed in it, preferably deeper than the notches4, and the notches 5 in the bricks of superposed courses cooperate toafford vertical communication between the chainbers or spaces in thebricks in said courses. Preferably these bricks or blocks are made ofsilicon carbide, carborundum, or the like. although they may also bemade of fire clay, or any other suitable material.

The second course from the top in the front section of the wall shown iscomposed of bricks D and D, and, as best shown in Fig. 2, each of thesebricks is of approximately T-. shape in central horizontalcross-section. Each brick has a front wall or body portion ofapproximately the same thickness as the front wall of the brick.C, auditalso has a vertical flange or projection 6 extending rearwardly from thecentral portion of said front wall, this flange having a notch 7therethrough of approximately the same dimensions as one of the notches4 of the bricks C above described. Each of these bricks D and D also hasplate-like extensions or flanges 10 at the top and bottom thereof, theseflanges being cut away or notched so that when they are placed side byside in a course, as shown in Fig. 2, a space or notch 12 is formed.between them of the same dimensions as the notches 5 in the bricks C.The bricks D are of exactly the same construction as the bricks D exceptthat the vertical flange 6 of the brick D is not notched but is recessedor apertured, as shown at 8, to receive the angular end of a tie bar 9,the shank of which is anchored in the rear section A of the wall.

The bricks E in the second course from the bottom, Fig. 1, are of thesame construction as the bricks C except that they are each providedwith two apertures or holes 14: formed through the front wall thereoffor the passage of air into the furnace chamber or the fuel bed.

The blocks F in the lowermost course, Fig. l, are like the blocks Dexcept that they are provided with air discharging apertures 15 similarto the apertures 14.

The rearwardly extending flanges or projections of all these bricks areof substantially the same height as their respective bricks, and thebricks are of uniform dimensions from their front faces to the rearedges of their flanges. Consequently, in building the front wall sectionB from these bricks the ends of the flanges are abutted against the rearwall A, and the flanges therefore definitely space the front walls ofthe bricks from the rear wall section A. It should also be observed thatthe two upright end flanges 22 of any pair of abutting bricks C aresuperposed upon the central flange 6 of the bricks D in the next lowercourse. These flanges 6, in turn, are placed directly upon the endflanges 22 of the bricks E, and the latter are superposed upon thecentral flanges 6 of the bricks F. In other words, the vertical flangesof the bricks ofeach course are superposed upon the vertical flanges ofthe bricks in the next lower course. Preferably, also, the verticalflange 6 of each brick D or F is substantially equal in width to thecombined thickness of the abutting flanges 22 of the bricks in thecourses C and E. Since each flange is continuous for the entire heightof its respective brick, the superposed flanges cooperate to formvertical supports extending from the top to the bottom of the frontsection and from the front to the rear of said section. This provides afront wall section which is very strong and rigid mechanically, thefront section is braced against the rear section A by the contact of theflanges with said rear section, and it may be tied to the rear section.by the tie bars 9.

At the upper edge of the front section as illustrated the divided wallends, and a solid wall is superposed upon it, the lower course of brickin this solid wall being shown at G, Fig. 1. A suitable arrangement forsupplying air to the space between the front and rear wall sections Band A, is to provide a space 16, Fig. 4, in the section A immediately atthe rear of the top course of hollow bricks, this space extendingpractically for the entire length of the front section. One or more airducts 17 lead air under pressure into the space 16. and the air flowsdownwardly through the superposed notches 5 and 12 to the bricks in thelower courses which may be provided with air discharging openings 14 and15. Air escapes through these openings into the fuel bed or into thecombustion chamber in the furnace. In some installat-ions, also, aheader or space similar to that shown at 16 is provided at the lower endof the front wall section A, and air ducts (not shown) comn'iuuicatingwith it conduct the air away from the space between the wall sections.As the air circulates between the front and rear sections of the wall,it flows against the rear surfaces of the body portions or front wallsof the bricks C, D, E and F, and carries the heat away from theseportions of the bricks, thus keeping the temperature of the frontsection of the wall within the desired limits. The flanges also assistin keeping the front wall of the brick cool since they conduct heat fromthis wall to the air and they expose a large heat radiating surface tothe action of the cooling current of air. The lateral communicationafforded by the notches 4 and 7 in the vertical flanges of the brickspermits a free horizontal flow of air between adjacent vertical aircolumns and equalizcs an variations in pressure laterally bet-ween dierent parts of the air space provided in the wall. A very freecirculation of air thus is provided immediately behind, and in contactwith, the front wall portions of the bricks C, D, E and F so that thedesired advantages of uniform and eflicient air cooling are obtained. Atthe same time this construction has the advantage of added mechanicalstrength and stability.

The T-shaped bricks D are shown on a larger scale in Fig. 5 which is aperspective View of the top and rearward side of one of these bricks.This view shows very clearly the plate-like extensions 10-10 extendingrearwardly from the top and bottom of the front wall or body portion ofthe brick, the vertical web 6 which, with portions of the extensions10-10 form the central upright flange'or projecting portion, and thenotch or passage 7 in this flange. It will be ob served that the rearpart of this brick is chambered out at opposite sides thereof for thegreater part of its height, thus making. the intermediate portion of thevertical flange 6 relatively thin, and at the same time providing afront wall which is comparatively thin,

say for example, two and one-half inches in thickness. The thin frontwall is of advantage, when the brick is made of silicon carbide orsimilar refractory material, in effecting a more rapid transmission ofheat from the front face of the brick to the rear surface where thisheat is swept away by the cooling current of air. This construction isespecial- 1y advantageous in permitting a more accurate control of thetemperature at the front face of the brick, and in being very economicalof material, which is an important consideration in bricks made ofsilicon carbide.

The deep grooving of the back of the block and the construction of theflanges permits a free circulation of air against the rear surface ofthe front. wall of the brick, so that the differences in temperature ofthe flanges and the front wall or body portion of the brick is greatlyreduced, and the internal stresses set up in the brick by changes intemperature are correspondingly reduced.-

This practically eliminates the difliculties which have been experiencedwith prior co'nstructions of bricks in the breaking off of the flangesfrom the front wall or body portion which have proved a very seriousobjection to such constructions.

When a brick of this general type is to be made of tire clay, therearwardly extending Vertical flange 6" is preferably not chambered outat opposite sides,as shown in Fig. 5 .but the flange preferably is madeas shown in Fig. 10, the bricks shown in these two figures, in otherrespects, being the same. It will be observed that the flange 6 of thisbrick is very wide where it joins the body portion of the brick andgradually decreases in width as it extends rearwardly. This flange 6 issubstantially the same size throughout its length as the face or end 10thereof. This construction, therefore, is better adapted for a cla lv'brick than the design shown in Fig. 5 which includes thinner and morefragile parts. At the same time the brick shown in Fig. 10 is welladapted for use in walls which are not subjected to sufficiently hightemperatures to make advisable the use of bricks made of siliconcarbide.

In all of the bricks used in the front section B of the wall, we preferto provide the edges of the body portions with'tongues 18 and grooves 19so that the front walls or body portions of these bricks will beinterlocked with each other or bonded together by this tongue and grooveconstruction. This facilitates the laying of the bricks and in ofadvantage in securely holding the front portions of the bricks in thewall even if the flanges of certain of the bricks should become crackedor broken off.

Figs. (3 and 7 show the brick F. Fig. 1, on a larger scale, this brickbeing like the brick D, Fig. 5, except that it is provided with taper-edair discharging apertures 15. Fig. 8 shows a brick H like that shown inFig. 5 except that it is provided with two air discharging apertures.The brick K, Fig. 9. is like the brick F except that its flange 20 isnot notched but is provided with a slot or passage 8 like that in thebricks D, and for the same purpose, namely,'to receive the angular endof a tie bar 9. In addition, the slots 8 of the bricks D and the slots 8of the bricks K also perform the same functions as the notches 7 inpermitting a horizontal or lateral flow of air through the spaces at thebacks of the bricks. In the construction shown the top and bottom edgefaces of the flanges are flush with, and form continuations of, the topand bottom edge faces of the front wall or body portion of the brick.\Vhile this is the preferred construction, particularly when the methodil lustrated of tying the front and rear wall sections together is used,it will be evident that the invention is not limited to this particularconstruction.

The. bricks provided by this invention require less material in theirconstruction than prior bricks of which we are aware and which aredesigned to perform the same functions. they facilitate the building ofthe front section of the furnace wall, and a wall construction made fromthem has unusual mechanical strength and rigidity.

\Vhile we have herein shown and described the best embodiment of ourinvention that we have so far devised, it is contemplated that theinvention may be embodied in other forms without departing from thespirit or scope thereof. It will be understood that the furnace wallbuilt in the manner above described may constitute only a portion 01section of the entire height of the whole wall and this often is thecase in practice, the air cooled wall extending only through that regionwhich is subjected to higher temperatures.

The box-type of block above mentioned is not claimed in thisapplication, but it is claimed in another application filed of even dateherewith, Serial No. 85,683.

Having thus described our invention, what we desire to claim as new is:

1. A furnace wall structure comprising superposed courses of bricks,composed entirely of refractory'materials, the bricks in one coursebreaking joints with those in the next course. said bricks havingupright rearwardly projecting portions with the projecting portions ofthe bricks in one course superposed on the projections of the bricks inthe next lower course. said wall having vertical air passages acrossadjacent courses, formed by said portions, to permit a vertical flow ofair past the rear faces of the bricks.

2. A furnace wall structure comprising superposed courses of bricks,composed entirely of refractory materials, the bricks in one coursehaving upright projections extending rearwardly from opposite endsthereof and the bricks in the next adjacent course each having anupright projection extending rearwardly from the central part thereof,said projections in one course overlying those in the next lower course,said wall having vertical air passages across adjacent courses formed bysaid flanges.

3. A furnace wall structure comp-rising superposed courses of brickscomposed entire- 1y of refractory materials, the bricks in one coursehaving upright projections extending rearwardly from opposite endsthereof and the bricks in the next adjacent course each having anupright projection extending rearwardly from the central part thereof,the two adjoining end projections of bricks in one course being alinedwith the central projection of a brick in the next lower course.

4. A furnace wall structure having front and rear sections of fireproofmaterial, said front section comprising superposed courses of bricksmade of highly refractory material having upright rearwardly projectingportions abutting against the rear section and thereby spacing a part ofsaid front section from said rear section, the projecting portions ofthe bricks in one course overlying the projecting portions of the bricksin the next lower course, said wall having vertical air passages acrossadjacent courses, formed by said portions, and permitting a. circulationof air between said front and rear sections.

5. A furnace wall structure having front and rear sections of fireproofmaterials, said front section comprising superposed courses of bricksmade of highly refractory materials having upright rearwardly projectingportions abutting against the rear section and thereby spacing a. partof said front section from said rear section the projecting portions ofthe bricks in one course overlying the projecting portions of the bricksin the next lower course, said wall having vertical air passages acrossadjacent courses formed by said portions and means cooperating withcertain of said projecting portions to tie said front and rear sectionstogether.

6. A furnace wall structure having front and rear sections of fireproofmaterial, said front section comprising superposed courses of bricksmade of highly refractory material raving upright rearwardly projectingportions abutting-against the rear section and thereby spacing a part ofsaid front section from said rear section, the projecting portions ofthe bricks in one course extending rearwardly from opposite ends of thebricks and the bricks in the next adjacent course each having itsprojecting portion extending rearwardly from the central part thereof,the two adjoining end projecting portions of bricks in one course beinga-lined with the central projecting portion of a brick in the next lowercourse.

7. A brick for furnace wall construction comprising a relatively thinfront wall, flat platelike extensions projecting rcarwardly from saidwall at the top and bottom thereof, said extensions being wide at saidwall and decreasing in width as they extend rearwardly, and a relativelythin upright web project-- ing centrally from the back of said wall andconnecting said extensions.

8. A furnace wall having front and rear sections of fireproof material,said front section comprising superposed courses of bricks made ofhighly refractory material the bricks in one course breaking joints withthose in the next course and having upright rearwardly projectingextensions abutting against said rear section with the extensions of thebricks in one course overlying the extensions of the bricks in the nextlower course, said extensions in each course being laterally spaced fromeach other and cooperating to form verical air passages between saidwall sections, the extensions being shaped to afford lateralcommunication between said passages.

9. A furnace wall structure con'iprising superposed courses of bricks,the bricks in one course breaking joints with those in the next course,the bricks in one course having upright extensions projecting rearwardlyfrom opposite ends thereof and the bricks in the next adjacent courseeach having an upright extension projecting rcarwardly from the centralpart thereof, said center extension of each brick in one course beingsuperposed on, and substantially equal in width to, the two endextensions of abutting bricks in the next lower course. said extensionsbeing substantially equal in height to the height of their respectivebricks, and certain extensions having cut away portions to providecommunication between opposite sides thereof.

10. A brick for furnace wall construction comprising a body portionforming the front wall of the brick, and a continuous upright extensionprojecting rearwardly from the central part of said body portion and ofsubstantially the same height as said body portion, said brickconsisting of refractory material and said extension being approximatelyas wide as said body where it joins the body and decreasing in width asit extends rearwardly, and having a cut away portion providingcommunication between opposite sides of said extension.

11. A brick for furnace wall construction comprising a relatively thinfront wall, flat platelike extensions projecting rearwardly from saidwall at the top and bottom thereof, with their upper and lower faces,respectively, forming substantially continuations ofthe top and bottomfaces Oi said wall, said extensions being relatively wide at said welland decreasing in width as they extend rearwardl and an upright web proecting rearwardly from said wall and connecting said extensions.

12. A furnace wall having front and rear sections separated bysubstantially continuous vertical supports spaced laterally from eachother to provide vertical air passages between said scctions,said frontsection including superposed courses of bricks made of re tractormaterial and having upright rearwardl v projecting extensions abuttingagainst the rear section, the bricks in one course breaking joints withthose in the next course, the extensions of the bricks in one courseoverlying extensions of the bricks in the next lower course, and saidextensions in superposed courses being included in said supports, saidextensions being shaped to provide lateral air passages between saidvertical air passages.

13. A furnace wall having front and rear sections, said front sectionincluding superposed courses of bricks. the bricks in one coursebreaking joints with those in the next course, the bricks in one coursehaving upright extensions projecting rearwardl from opposite endsthereof and the bricks in the next adjacent course each having anupright extension projecting rearwardly from the central part thereof,the-center extensions of the bricks in one course being superposed onthe two end extensions of abutting bricks in the next lower course, saidextensions abut-- ting against said rear section of the wall, wherebythe extensions cooperate to form substantially continuous supportsseparating said front and rear wall sections arid providbered out atopposite sides thereof, whereby V said intermediate portion is maderelatively thin.

15. A brick for furnace wall construction comprising a body portionforming the front wall of the brick, a continuous upright extensionprojecting rearwardly from said front wall and of substantially thesame.

height as said wall, said extension being Wide at said wall anddecreasing rapidly in width as it extends rearwardly, the intermediateportion of said extension being chambered out at opposite sidesthereof'for the greater part of its height, whereby said intermediateportion is made relatively thin, and a notch formed in the rearward edgeof said intermediate portion to provide for a free flow of air betweenthe chambers formed at opposite sides of said extension.

In testimony whereof we have signed our names to this specification.

OSCAR NYGAARD. BENJAMIN H. SNOW.

